There is something definitely very wrong here, but maybe it is me - I'm still
living in the dark ages.

I've set LANG=C in my .profile and .bashrc so I should avoid all these issues
now.

I came across this when I sorted 2 files, then used "join" to join them. It
complained that they were out of order. It seems that doesn't work any more -
you need to add args to at least one of the commands.